package org.apache.lucene.index;

/**
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

/** @lucene.experimental */
public final class FieldInfo {
    final String name;
    final int number;

    boolean isIndexed;

    // true if term vector for this field should be stored
    boolean storeTermVector;
    boolean storeOffsetWithTermVector;
    boolean storePositionWithTermVector;

    public boolean omitNorms; // omit norms associated with indexed fields  
    public IndexOptions indexOptions;

    boolean storePayloads; // whether this field stores payloads together with term positions

    /**
     * Controls how much information is stored in the postings lists.
     * @lucene.experimental
     */
    public static enum IndexOptions {
        /** only documents are indexed: term frequencies and positions are omitted */
        DOCS_ONLY,
        /** only documents and term frequencies are indexed: positions are omitted */
        DOCS_AND_FREQS,
        /** full postings: documents, frequencies, and positions */
        DOCS_AND_FREQS_AND_POSITIONS
    };

    FieldInfo(String na, boolean tk, int nu, boolean storeTermVector, boolean storePositionWithTermVector, boolean storeOffsetWithTermVector, boolean omitNorms, boolean storePayloads, IndexOptions indexOptions) {
        name = na;
        isIndexed = tk;
        number = nu;
        if (isIndexed) {
            this.storeTermVector = storeTermVector;
            this.storeOffsetWithTermVector = storeOffsetWithTermVector;
            this.storePositionWithTermVector = storePositionWithTermVector;
            this.storePayloads = storePayloads;
            this.omitNorms = omitNorms;
            this.indexOptions = indexOptions;
        } else { // for non-indexed fields, leave defaults
            this.storeTermVector = false;
            this.storeOffsetWithTermVector = false;
            this.storePositionWithTermVector = false;
            this.storePayloads = false;
            this.omitNorms = true;
            this.indexOptions = IndexOptions.DOCS_AND_FREQS_AND_POSITIONS;
        }
        assert indexOptions == IndexOptions.DOCS_AND_FREQS_AND_POSITIONS || !storePayloads;
    }

    @Override
    public Object clone() {
        return new FieldInfo(name, isIndexed, number, storeTermVector, storePositionWithTermVector, storeOffsetWithTermVector, omitNorms, storePayloads, indexOptions);
    }

    void update(boolean isIndexed, boolean storeTermVector, boolean storePositionWithTermVector, boolean storeOffsetWithTermVector, boolean omitNorms, boolean storePayloads, IndexOptions indexOptions) {

        if (this.isIndexed != isIndexed) {
            this.isIndexed = true; // once indexed, always index
        }
        if (isIndexed) { // if updated field data is not for indexing, leave the updates out
            if (this.storeTermVector != storeTermVector) {
                this.storeTermVector = true; // once vector, always vector
            }
            if (this.storePositionWithTermVector != storePositionWithTermVector) {
                this.storePositionWithTermVector = true; // once vector, always vector
            }
            if (this.storeOffsetWithTermVector != storeOffsetWithTermVector) {
                this.storeOffsetWithTermVector = true; // once vector, always vector
            }
            if (this.storePayloads != storePayloads) {
                this.storePayloads = true;
            }
            if (this.omitNorms != omitNorms) {
                this.omitNorms = false; // once norms are stored, always store
            }
            if (this.indexOptions != indexOptions) {
                // downgrade
                this.indexOptions = this.indexOptions.compareTo(indexOptions) < 0 ? this.indexOptions : indexOptions;
                this.storePayloads = false;
            }
        }
        assert this.indexOptions == IndexOptions.DOCS_AND_FREQS_AND_POSITIONS || !this.storePayloads;
    }
}
